You may be required to produce a pay stub from your last job. Would you rather not (maybe because you fudged your salary history)? That might be grounds for automatic termination.
You may be required to sign a very restrictive non-compete agreement. Rather not? Empty your desk.
Your employment may be subject to a urinalysis. Rather not “give”? You must be hiding something. Bye.
The employee manual, which lots of companies won’t give you until your first day, may require you to turn over all sales accounts (that you brought with you) to another sales rep. No? See ya later.